Leach, a former adviser to the UK government on telecommunications, will be deported on his release.

Five Cambodians, including the mothers of two of the victims and a guesthouse owner, also received sentences for acting as accomplices in child prostitution.

'Tip of iceberg'

A Ceop spokesman said: "We welcome this conviction and the response of the Cambodian authorities in bringing Michael Leach to justice.

"While not directly involved in this particular prosecution, Ceop continues to be active working with governments, law enforcement and NGOs in the South East Asian region to safeguard children from sexual abuse and hold offenders to account for their crimes."

But David Thomson, of World Vision, the charity which is now caring for Leach's victims, said it wanted the co-operation between the UK and Cambodia extended to all paedophile "hotspots".

"Of course it is great that they have been able to work together for a successful outcome: but this is just the tip of the iceberg," he said.

He said that in one project alone in Cambodia in 2009, the charity had referred 53 abused girls to courts.